Preheat your oven to 350°F and spray a loaf pan with cooking spray, making sure to coat the bottom and all sides evenly. This prevents sticking and ensures clean edges on your finished bread. Have all ingredients at room temperature before you begin mixing—this is especially important for the eggs and eggnog, as they'll incorporate more smoothly into the batter.

In a medium bowl, whisk together the flour, sugar, salt, baking powder, cinnamon, and the larger portion of ground nutmeg (1/4 tsp). Whisking rather than just stirring helps distribute the leavening agent and spices evenly throughout the flour, which ensures consistent flavor and rise in every slice. Set this dry mixture aside.

In a separate bowl, whisk together the room-temperature eggnog, vegetable oil, eggs, vanilla extract, and rum extract until well combined and slightly frothy. The room-temperature eggnog is key here—cold ingredients won't blend as smoothly and can result in a slightly dense crumb. Whisking creates emulsification, which helps the oil and eggnog incorporate evenly for a tender, moist bread.

Pour the wet ingredient mixture from Step 3 into the bowl with the dry ingredient mixture from Step 2. Stir gently with a spatula until just combined—you want the batter to come together, but don't overmix. I always stop when I see just a few streaks of flour remaining; overmixing develops gluten and creates a tough, dense crumb instead of the tender, moist texture you're aiming for in quick breads.

Pour the batter into your prepared loaf pan, smoothing the top gently. Bake for 65–70 minutes, until a toothpick inserted into the center comes out clean or with just a few moist crumbs. Start checking around the 60-minute mark since ovens vary. The bread should be golden brown and a skewer should meet only slight resistance as it goes through.

Remove the bread from the oven and let it cool in the pan for 15 minutes on a wire rack. This resting period allows the bread to set slightly and makes it easier to remove without crumbling. After 15 minutes, turn the bread out onto the rack and let it cool completely to room temperature. This full cooling is important before glazing, as a warm glaze will run off a hot bread.

While the bread cools, whisk together the sifted powdered sugar, room-temperature eggnog, vanilla extract, rum extract, and the smaller portion of nutmeg (1/8 tsp) until smooth and pourable. I always sift the powdered sugar first to remove lumps, which ensures a silky, lump-free glaze. Once the bread is completely cooled, drizzle the glaze generously over the top, allowing it to drip down the sides. Let the glaze set for a few minutes before slicing and serving.